Pusher having movable pads



May 27, 1958 J. R. cox

' PUSHER HAVING MOVABLE PADS Filed Oct. 4. 1954 23 I F2 H [fii MUM MW 24 %m\\rn Fig.1

IN V EN TOR.

Fig.5

JOHN "R. COX

United rates Patent PUSHER HAVING MOVABLE PADS John R. Cox, Cleveland, Ohio Application October 4, 1954, Serial No. 460,035

' 4 Claims. (Cl. 27955) My invention relates to pushers or feeders for advancing stock in a machine tool, such as an automatic screw machine.

An object of my invention is the provision in a pusher for positioning stock-engaging pads in a pusher in accordance with the axis of the stock engaged by the pads.

Another object is the provision for aiding in the insertion of stock into a pusher from the rear end of the pusher.

Another object is the provision for permitting removable pads in a pusher to rock or tilt so as to cause shifting of the position of the pads in accordance with the surface of the stock being engaged by the pads.

Another object is the provision for having pads in a pusher accommodate themselves to variations in the position of the resilient fingers of a pusher.

Another object isthe provision for providing maximum engagement between the pads of a pusher and the stock positioned between the pads along the axial length of the pads.

Another object is the provision for eliminating gouging or scratching of bar stock by pads in a pusher should be not in true parallel relationship to the axis of the stock being engaged.

Another object is the provision for permitting limited tilting or rocking between limits of pads in a stock-advancing pusher.

Another object is the provision for producing results not heretofore obtainable by means no heretofore known.

Other objects and a fuller understanding of my invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing, in which:

Figure 1 is an elevational view partly in section showing my pusher device and accommodating cylindrical stock therein;

Figure 2 is a cross-sectional view taken through the line 22 of Figure 1;

Figure 3 is a longitudinal sectional view taken through my device at the forward end thereof and illustrating the initial feeding of a bar of stock into the pusher;

Figure 4 is an endwise view of my device looking in the direction of the arrows 4-4 of Figure 3; and

Figure 5 is an enlarged sectional view of a portion of 7 my pusher at the forward end thereof and accommodating a piece of stock therein.

An example of a pusher embodying my invention as shown in the drawing has a body 11 of general cylindrical form. The rear end of the body 11 is threaded to threadably engage the machine utilizing the pusher.

The pusher has three resilient fingers 12, 13 and 14 provided by longitudinally extending slits extending from the forward end of the pusher. In an untensioned condition, the fingers 12, 13 and 14 slope slightly inwardly and forwardly, but in a position holding stock, such as in Figure 5, fingers 12, 13 and 14 extend substantially straight so that together they form a cylindrical continuation of the body 11.

2,836,425 Patented May 27, 1958 At the forward end of the pusher, there is a portion 'ice adapted to accommodate stock-engaging pads or jaws 18, 19 and 20, respectively. One pad is carried by each of the three fingers. There are two longitudinally spaced walls 15 and 16 extending radially inward of the pusher and the pads are positioned between these spaced walls. The forward wall 15 holds the pads against moving forwardly of the pusher and the rearward wall holds the pads against moving rearwardly of the pusher.

Intermediate the spaced walls 15 and 16 there is an inwardly extending rib or projecting portion 17. The rib 17 is annular in form to extend around the pusher at its forward end. The inward radial height or extension of the rib 17 of the three fingers is less than the height or radially inward extension of the walls 15 and 16. On opposite sides of each rib 17 there is an inner wall 21 and an inner wall 22, the inner wall 21 being forwardly of the rib 17 and the inner wall 22 being rearwardly of the rib 17. Because of the inward projection of the rib 17, the wall of the pusher is thus relieved on opposite sides of the rib and intermediate of the walls 15 and 16. The relative dimensions and the contour and shape of the parts are substantially as those shown in the views of the drawing.

There is a bore 23 extending through the pusher and there is shown a cylindrical piece of bar stock 24 positioned in the pusher. The inner surfaces of the pads are adapted to engage the outer surface of the cylindrical stock-'24. By reason of the resilient compression of the fingers, the pads are urged radially inward and into tight engagement with the stock 24.

Among the several advantages of the construction shown is the advantage of having the pads rock or tilt to a limited degree within the pusher so as to position them correctly in accordance with the axis of the stock accommodated in the pusher. Sometimes the fingers, by reason of heat treatment and the like, may not be perfectly true and symmetrical relative to the axis of the pusher, and when so unsymmetrical, a fixed pad carried by a finger may not be perfectly aligned with the stock accommodated in the pusher. However, with this invention, the pad may tilt so that the inner cylindrical wall of a pad may be perfectly aligned with the axis of the stock. An example is given in Figure 5, showing that the pad 18 has tilted slightly so that it is closer at its forward end to the wall 21 than it is at its rearward end to the wall 22. However, the inner surface of the pad 18 is in true parallel relationship with the axis of the stock. If the pad 18 in this view had not been permitted to slightly tilt, then the forward inner corner of the pad 18 would be closer to the axis of the stock than the remaining inner surface of the pad and thus tend to gouge into or scratch the stock. This tendency, however, has been eliminated by permitting the pad to tilt and to accommodate its position to the true axis of the stock.

Another advantage of my invention is illustrated particularly in Figure 3. In this figure, it is shown that the forward end of the bar stock being introduced into the bore between the three pads must overcome the resistance set up by the radial inward compression of the pads. By the construction shown, all three pads may tilt to the position shown in Figure 3, wherein the rearward end of the pads moves radially outwardly toward the wall 22 adjacent the end wall 16. At the same time, the forward ends of the pads have moved radially inward of the pusher away from the wall 21 adjacent the end wall 15. As the stock 24 is advanced forwardly in the pusher, each to the position shown in Figure 1, then the pads tilt back into proper alignment so that the inner surfaces of the pads are in proper parallel relationship with the axis of the stock. After the stock has been appended claims l aswell as th ferred 'formiwith 'acertain. degree; of; particularity it is V understood: that :the present disclosure of therspreferred formshas beenz made only-by, wayiof :exaniple -and that 15 unframed into the pusher, then the pads take the parallel position'shown in Figure 1.

'A tongue 25 extends into a recess in one pad 19 so as to.-prevent:=revolving ofsftherpadswithin theepusherfz :It has been found that devicesaembodying; my inven- 5 tionrhave provided surprisingly beneficial results and? havegreatlyincreased the efiiciency of pushersand made numerous-changes in' the details of constructionand then combination and arrangement of parts 'may-ibe resorted a to? without.departingafrom thespiritand; scope -of;- the:- invention as hereinafter claimed; a 1

7 What is claimed is: V i V 7' A pusher having'a pluralitytof resilient fingers at its-forward end; each of said fingers having axially" spacedinternal shoulders extendingradially inward of the cylindrical pjusher bore for receiving a pad therebetwfeen within the said bore, each of said fingers-havinganj;

internal rib extending radially. inward of saidibore. and? intermediate of said spaced shoulders, saidrrib extend-f inggra'dially, inward lessthan the inward radial extent of saidspaced shoulders to provide a fulcrum support-fora? said-pad, theinternalwall of said pusher bore on op-3Q po'site sides' of" said rib being. greater in diametergthanv the internal diameter'oftthe pusher at said ribandi-being-f cfrsu'c h diameter asto' permit a pad between the :shoul ders of a said fingerjto tilttrelative to the pusherq'axis '7 'while intermediate said shoulders for accommodating the position of the pads to stock engagedjby thesaidfpadsn 2.- T A pusher having resilient'fingersat itsaforward end,-

at set forth in the foregoingw 1 V projecting portion from said axis, saidtpads 'being tiltsaid-fingers adjacent said forward end'bein g'iformed to receiving bore, each of said fingers having inwardly ex-;

:1 said pad maybe positioned, eachofsaid fingers having-; an Vinner'wall intermediate said spaced walls, each of" saidifingers --having';a fulcrum portion-formed on,-: and

receive-stock-engaging;pads" arranged around a stock 7 40 tendingaa'nd longitudinally spaced walls -between -which:

extendingradially inward from, said inner wall at a -lo'" cation between said spaced walls, said fulcrum portion I providing a fulcrum for a said pad to permit the sameto" tilt between said spaced walls ,relativeto the axis of-l the pusher between limits determined by the distance or said inner wall from said,axis,-said distance at locations ad-"1" distance jacent said spaced walls being greater than'the from said axis to said fulcrum portion.

extended walls spaced axially apart'to receive apad therebetween, each of said fingers having a fulcrum per- 7 tion projecting radially inward intermediate J of? said spaced walls and engaging a said pad intermediate of its longitudinal ends, said fingers being relieved; radially outwardvon oppositesides of said' fulcruin' portion zto permit a said pad to rock on said fulcrum portion relative; to theaaxis of said pusher, the rocking of saidpads pro-' viding;:for-' the accommodation ofthe positionofvsaid pads :to stock inserted; in the pusher. p 1

t 4;. A pt' sher' device comprising the combination= of 'a cylindrical pusher body having forwardlytaperedrre-f silient fingers, and stock-engaging pads positioned in'the pushenadjacent its forward en'd;eachsaid finger-having" inwardlyeextending t and longitudinally. spaced Wallsfor-i accernrnodating apad the'rebetweeh, each said finger hav-; ing a projecting portion extending'inwardly, of the pusher-'5'- V interniedaite said:spaced"walls, each oflsaid pads-renga'ge ingwa rsaidzprojecting portion intermediate "of ther longi radialsdis'tance greater: than' the radial distance? Of-i Said' able on the 'respectiveprojecting portions relative to' said axis: 7 v V V V 7 References Cited in the file of patent- 1 June 13,1939 

